Braun oscillograph



March 12, 1935. J RlcHTER ET AL 7 1,993,858

BRAUN OS 0 ILLOGRAPH Filed May 16, 1930 INVENTORS JOHANNES RICHTER A ERT A NE BY LB KNB R ATTORNEY Patented Mar. 12, 1935 X j 1,993,858

I ED OFFICE? Johannes Richter and Albert Knabner, Berlin,

Germany, assignors to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. 11., Berlin,

Germany, a corporation of Germany Application May'lG, 1930, Serial No. 452,880 In Germany May 17, 1929 3 Claims. (01. 250-275) The Braun oscillograph is extensively used in By the accompanying drawing, Fig. 1 illustrates the analyses of alternating currents. One of the I a sectional view through a completely assembled recent developments in the construction of these tube, and Figs. 2, 3 and 4 indicate the arrangetubes is that they have been equipped with heated ment of the filamentary cathode within the tube,

5 cathodes. Figs. 2 and 3 showing the filamentary cathode 5 The present invention resides in various imtransverse to the tube axis and Fig. 4 showing the provements of such a tube, and the advantages filamentary cathode longitudinally of thetube of the same concern both the manufacture and axis. I the technical end of the tube as well as the longer Referring to the drawing, H is the heated filalife and greater sensitivity or the tube. Acco-rdment spiral, B the cup-shaped or beaker-shaped 10 ing to the invention, the cathode, which may diaphragm surrounding the said spiral. The consist of a heated spiral positioned at right anode A is sealed in the glass bell G, and at its angles to the tube axis, is surrounded by a bowl lower end it is located in front of the diaphragm or cup-shaped diaphragm. The latter, being opening D. F is the glass cup which serves for most suitably mounted together with the glass mounting the electrode assembly. -As shown by 5- cup wherein the filament is contained, is pro- Fig. 1 aBraun tube T according to the invention, vided with a separate lead-in so that a biasing is provided with the usual fluorescent screen potential may be applied thereto with a view to S, formed as-above described and P and P repre increasing the sensitiveness. By the particular sent the deflecting plates, vfor obtaining horishape of the diaphragm, a separate cathode space zontal and vertical deflections of the cathode ray 20 is obtained inside the tube, while by the use of a stream. These plates are preferably formed biasing potential the emission of the cathode has from non-magnetic material, such as German to be lower, for a given thermionic current flo-wsilver. The showing of the cup shaped member ing through the anode channel. This'in turn F and the manner ofassembling the filamentary means longer life of the tube. a

The anode, which may consist, for example, Figs. 2 and 3 which represent onfan enlarged. of a slender metal tube, for example, a platinum scale the showing in Fig. 1. By Fig. 4 certain" tube, is sealed inside a glass bell, the end of which modifications and changes have been made to suitably is flush with the glass bell. The beakerillustrate the formation of the j filamentary cathode H therein is shown in further detail by 25 shaped diaphragm has: a hole at its anterior end, cathode as extending longitudinally of the tube.

the diameter thereof being somewhat larger than Having now described our invention, what we the diameter of the anode tube. The glass bell claim and desire to secure by Letters Patent is is fitted upon the diaphragm, and the anode can the following: v

be easily centered into the diaphragm opening. 1. A cathode ray tube comprising a cathode The diaphragm opening towards the'inside of member for emitting a cathode ray stream, a 35 the beaker may be of a smaller diameter than non-metallic cup substantially surrounding the in outward direction. During the evacuation cathode and for supporting said cathode member, process the diaphragm. can be effectively outa diaphragm member carried by the non-metallic gassed by applying positive potential thereto. It cup and extendingoutwardly from said cathode 40 is desirable to use an oxide cathode and also adfor limiting thepath of the cathode rays'emitted, 40 visable to form the deflector plates and the eleca fluorescent screen, and a tubular shaped anode trode supports from a readily weldable nonmember mounted within said diaphragm for promagnetic metal, such as German silver. For jecting the cathode rays toward the fluorescent the luminescent screen the use of fluorescent subscreen.

stances as extensively used for these purposes is 2. A cathode ray tube having a multi-turn 45 recommendablathough especially favorable is spiral oxide coated cathode member positioned the admixture of halogens and their compounds, transversely to the tube axis, an insulating memsuch as iodine, to the fluorescent material whereber for supporting the cathode, a tubular anode by firm sticking of the fluorescent substance to member, a diaphragm supported from the r '50 the glass Wall isinsured. The anode protection cathode supporting member and having an openresistance most suitably is sealed inside the ing concentric with the'axis of the tubular anode, vacuous vessel. a supporting bell for positioning the tubular Theaccompanying drawing illustrates embodianode axially of the tube, a plurality of pairs of ments of the heated filament for a Braun tube non-magnetic deflecting electrodes positioned according to this invention. substantially adjacent the anode for deflecting in 55 a plurality of directions at right angles to each other the cathode ray upon application of voltages thereto, and a fluorescent screen adapted to become luminous upon the bombardment of the generated cathode rays.

V 3. A cathode ray tube having a cathode memher, a non-conducting member for supporting the cathode, a tubular anode member, a diaphragm supported from the cathode supporting member and having an opening concentric with the axis of the tubular anode, a supporting bell for positioning the tubular anode axially of the tube, at least one pair of non-magnetic deflecting electrodes positioned substantially adjacent the anode for deflecting the cathode ray developed within the tube upon the application of voltages to the said electrodes, and a fluorescent screen adapted to become luminous upon bombardment by the developed cathode ray.

J OHANNES RICHTER. ALBERT KNABNER. 

